<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Title</title>
</head>
<body>
<script>
const first = () => (new Promise((resolve, reject) => {
    console.log(3)
    let p = new Promise((resolve1, reject1) => {
        console.log(7)
        setTimeout(()=>{
            console.log(5)
            resolve(6)
        },0)
        resolve(1)
    })
    resolve(2)
    p.then(arg=>{
        console.log(arg)
    })
    first().then(arg=>{
        console.log(arg)
    })
    console.log(4)
}))
    // 同步：3 7 4 1 2 5
    // 宏队列：[5]
    // 微队列：[1,2]
</script>
</body>
</html>
